Propeller



July 13 1926, 1,592,031

G. LIPARI PROPELLER Filed Nov. 30, 5

, I FIGURE 4 FIGURE .5 FIGURE 6 FIGURE 7 FIGURE 8 INVENTOR 4 ATTORNEY Patented July '13, 192's.

PATENT OFFICE.

GAETANO LIPARI, OF SAN JOSE, CALIFORNIA.

PROPELLER.

Application filed November 30, 1925. serial No. 72,256.

It is the object of my invention to provide a propeller with'a higher efiiciency than the usual screw propellers, so that higher speed may be obtained through its use with substantially the same consumption of fuel and the same driving power, and one that will be exceptionally strong and durable.

In the drawing Figure 1 is a front elevation of my improved propeller.

,Figure 2 is a View of the same tilted for.-

vvardly and downwardly.

Figure 3 is a plan view of the propeller.

Figure 41 is a sectional view of the propeller on line 44 of Figure 1. p

Figure 5 is a sectional view of the propeller on line 55 of Figure 1.

Figure 6 isa sectional View of one of the I propeller blades on line 6-6 of Figure l.

Figure 7 is a front elevation of form of my invention. a s

Figure 8 is a plan view of thesame.

' Referring more particularly to the draw ing I show at 1 a propeller hub adapted to another engage a driving shaft along its axis of rotation 2 and provided with oppositely directed and symmetrically arranged blades- 33. The bases of the two blades 33 merge into one integral whole, the base of one blade curving around the central hub portion 1 and merging with the base portion of the other blade. This formation is clearly shown in Figure 3 where the face l of one blade is joined to the corresponding oppositely directed face of the other blade by continuing around and over the hubq-l in a torsional curved surface 5, the other two faces of the" blades being joined in a similar manner.

The nature of the curved surfaces 55 is of vital importance in this invention, these curved surfaces very closely approaching a the point 6 on one end of the hub 1 and. lying in a plane bisecting the blades and the axis of the hub longitudinally, and drawn over the lowest portions of the surface to point 7 diametrically opposite on the opposite end of the hub as indicated at 8, would lie almost entirely in the wall of a cylinder having a diameter the same as the hub 1.

One of the results obtained by curving the surfaces 55 in this manner is that it brings the heels 9 of the. blades close to the hub, the line passing through and bisecting either pair of opposing, heels 99 as at 10 being 'at substantially an angle of sixty degrees to the plane bisecting the hub axis and blades longitudinally.

' In order to secure the desired curvature of the hub 1 and securethe desired connecting surfaces between the two blades, it is desirable that each blade be turned at an angle of substantially eighty degrees from a plane bisecting the hub axis and blades longitudinally as indicated at 11. p

When a propeller of this formation is in use it offers a negligible resistance to the air at the hub, the resisting. surface being limited to the diameter of the hub itself. Theoretically it might be said that the air stream at this point as itflows past hub 1, the two blades being enabled to exert their full'power upon the air without the disturbing influence of a churning body of air around the hub 1.

1n Figures 7 and 8 I show another form of propeller in which the blades are continu ous around the hub at substantially the same angle as above set forth, but instead of having the length ofthe hub equal to the width of he blade as in the embodimentabove described, the hub' is lengthened-along its axls 12 and the blades 13 are connected through a smaller pair'of blades 14 extending at right angles to them along the hub. This form is eflicient in propelling boats while the propeller hereinbefore described is for use on aeroplanes. In this embodiment one edge of the large blades is curved as at 15 while their opposite edges 1-6are twisted midway t their length to form the small blades 14:. cyhn-drical form. In fact a line drawn from blade being continuous with the oppositely directed surface of the other blade, the lowest portion of the connecting surface passing around the hub in a substantially cylin- 5 drical form.

2. A propeller comprising a hub portion, and oppositely directed symmetrically formed blades formed integrally thereon,

said blades being angularly and oppositely directed with respect to a vertical plane bisecting them longitudinally, the bases of the two blades merging into one integral whole, either surface of one blade being continuous with the oppositely directed surface of the other blade.

GAETANO LIPARI. 

